The present invention relates to a counterblade extracting device, particularly for extracting the counterblades of trucks for shredding-mixing zootechnical fibrous products.
The use of shredding-mixing trucks with a vertical scroll to prepare fodder for livestock, in particular cattle, is known in the zootechnical field; said trucks are substantially constituted by a container in the shape of an inverted truncated cone arranged on a wheeled chassis inside which a scroll is arranged vertically; the profile of the helix of said scroll is arranged along an ideal conical surface.
Blades suitable for shredding the product being mixed, which is appropriately loaded from the top, are peripherally fixed to the scroll.
In order to contrast the rotary motion of the product being mixed, which is entrained by the rotating scroll, substantially radial counterblades are arranged at the lower part of the container and can be inserted and extracted through slots provided thereon.
Said counterblades are substantially constituted by disk sectors which are pivoted proximate to their vertex.
Extraction of the counterblades after insertion in the container can currently occur either simply manually, by means of handles appropriately applied to said counterblades, but this is particularly onerous due to friction and to the action exerted on said counterblades by the product inside the container, or by applying hydraulic jacks rigidly associated between the container and the blades.
However, the presence of the hydraulic jacks entails the execution of an offtake branch of the hydraulic circuit and necessarily entails the simultaneous actuation of all the counterblades, unless a distributor suitable for sending pressurized oil only to the desired counterblades is used.
This naturally entails rather considerable cost increases.